Granted Patent
Utility
US 4,050,479 · App. 05/693,420
Fluid resistance device
Inventor:
Hans D. Baumann
Patented Case
View Patent ↗
Granted: Sep 27, 1977
Filed: Jun 7, 1976
Inventor
Hans D. Baumann
Assignee (at issue)
Masoneilan International, Inc.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.